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Full-Text Articles in Engineering
Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry
Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry
Mechanical and Aerospace Engineering Theses
Increased application of composite materials in the military and civil applications renewed the interest to development of high-fidelity methodologies for predicting their performance characteristics. Besides the traditional autoclave processed structural composites such as IM7/8552 and IM7/977-3 widely used on various platforms, novel materials such IM7/5320-1 suitable for Out-of-Autoclave (OoA) cure became of interest. Static and fatigue performance prediction of Open-Hole quasi-isotropic laminates made from IM7/5320-1 was performed in this work by using the Finite Element Analysis software BSAM. Progressive failure simulation including delaminations, matrix cracks and fiber failure was performed. Regularized eXtended Finite Element Methods (RXFEM) was used for mesh …
Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi
Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi
Material Science and Engineering Theses
Metal-Organic Frameworks (MOFs) are a highly versatile class of materials with a wide range of potential applications in gas storage, separation, catalysis, drug delivery, and sensing. The ability to tailor the properties and functionalities of MOFs by varying the organic linkers and inorganic nodes makes them highly attractive for a wide range of applications. The unique properties of MOFs also make them promising materials for fundamental studies in materials science and chemistry. The current investigation focuses on the dispersion study of MOFs and the synthesis of MOF-Polymer composites. The dispersions of MOFs in various organic solvents like ethanol, isopropanol, tetrahydrofuran, …
Effects Of Metal Organic Frameworks In Polyether Block Amide Elastomer, Joe Alex
Effects Of Metal Organic Frameworks In Polyether Block Amide Elastomer, Joe Alex
Mechanical and Aerospace Engineering Theses
Metal-organic frameworks (MOFs) are highly porous materials that find extensive applications in gas absorption and separation in recent years. These hybrid materials can be designed with specific pore sizes and voids to selectively filter gases. PEBAX (MV 1074) is a commercially available polyether block amide copolymer generally used in gas separation applications. In this study, we characterize two different MOFs by means of a dispersion study and create a medium for them to be evenly dispersed into the aforementioned copolymer matrix. Polymer composite fibers are extruded using a twin-screw extruder and a winding unit at pre-determined parameters for winding speed …
Effects Of Graphene In High-Density Polyethylene Microfibers, Ashish Lal Sivadas Anilal
Effects Of Graphene In High-Density Polyethylene Microfibers, Ashish Lal Sivadas Anilal
Material Science and Engineering Theses
High-Density Polyethylene uniquely can induce banded spherulites as it is crystallized from its melt. We studied the effects of graphene in the crystallography of banded HDPE by examining parameters such as the extent of twisting, spherulitic growth, and nucleation density. The application of graphene as a multifunctional filler in polymer matrices is a great topic of interest because graphene at low concentrations can bring many improvements in mechanical, electrical, and thermal properties. We synthesized graphene oxide by chemical oxidation of graphite and further studied its effects in the twisted crystallography of HDPE. Three batches of fibers were extruded: two batches …
The Development And Characterization Of Piezoelectric- Magnetostrictive Smart Self-Sensing Composites, George Relebohile Qhonosheane
The Development And Characterization Of Piezoelectric- Magnetostrictive Smart Self-Sensing Composites, George Relebohile Qhonosheane
Mechanical and Aerospace Engineering Dissertations
The composites industry is expanding due to the growing global demand for high-performance materials. How do you ensure the production of composites is as smooth and effective as possible while maintaining the high quality of the material? The key issues in composites include crack occurrence, sticking to molds in the production process, and durability differences during their operation. However, monitoring such cases can be challenging. The industry is in need of a smart solution to be able to obtain accurate data from the raw material. This work focuses on the development of smart composite materials. The word composite comes from …
Coupled Effects In Dielectric And Thermal Properties Of Polymer Matrix Composite Structures Due To Moisture Absorption, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan
Coupled Effects In Dielectric And Thermal Properties Of Polymer Matrix Composite Structures Due To Moisture Absorption, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Fiber reinforced polymer (FRP) composites are being used in number of fields including aerospace, marine, sports, medical, power sectors, etc. due to their lightweight nature while retaining high mechanical performance in terms of high specific strength, stiffness, and great fatigue properties. However, the applicability of these materials is restricted by their stability up to a certain temperature (i.e. glass transition temperature) and environmental degradation (i.e. moisture, UV light, etc.). Moisture ingression greatly reduces their mechanical properties altering material structure by causing polymer plasticization, chain scission and fiber-polymer interface deterioration. These changes instantaneously affect the thermal properties of the materials which …
Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider
Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The long term behavior of composites have been extensively studied for the last four decades. Given the heterogeneity of these materials, the damage accumulation mechanisms lead to superior fatigue performance of composites compared to metals. However, due to the ‘sudden death’ behavior controlled by defect coupling, the precursor to fracture plane development of these materials, the challenge remains on how to assess the real-time material state and predict when it becomes critical? In the recent past, broadband dielectric spectroscopy (BbDS) has been used successfully to assess the material state and predict the material state change (triggered by defect coupling) for …
A Multiscale Study Of Cavitation Mechanism And Damage In Soft Materials, Fuad Hasan
A Multiscale Study Of Cavitation Mechanism And Damage In Soft Materials, Fuad Hasan
Mechanical and Aerospace Engineering Dissertations
Cavitation is defined as the formation and growth of the gaseous bubble in bulk liquid due to the tensile pressure followed by the violent collapse. The collapse of the bubble is particularly significant due to its potential to cause damage to relatively stronger materials by either creating pressure waves (symmetric collapse) or liquid jet (asymmetric collapse). The study of cavitation in soft materials (e.g., tissue, brain, gelatin gel, etc.) has, therefore, gained a fair share of attention in the scientific communities. Recent studies have indicated that cavitation could be one of the leading causes of the mild Traumatic Brain Injury …
Assessment Of Material State In Composites Using Global Dielectric State Variable, Vamsee Vadlamundi
Assessment Of Material State In Composites Using Global Dielectric State Variable, Vamsee Vadlamundi
Mechanical and Aerospace Engineering Dissertations
Composites are heterogeneous in nature and a fundamental understanding of the material response to applied mechanical, thermal, electrical and other multi-physical fields is required to efficiently design and synthesize the material system and demands attention to long-term behavior in particular. Unlike metals, composites are designed to develop distributed damage and initiation of a single microscopic crack does not individually affect the strength/life of these materials. Therefore, the primary interest is not in single local events but in the process of interaction of multiple events that have a collective global effect on the material behavior. The interaction of these local events …
Characterization Of 3d Printed Pla With The Help Of Mechanical, Di-Electric And X-Ray Diffraction Techniques, Sai Sri Nidhi Munaganuru
Characterization Of 3d Printed Pla With The Help Of Mechanical, Di-Electric And X-Ray Diffraction Techniques, Sai Sri Nidhi Munaganuru
Mechanical and Aerospace Engineering Theses
Additive manufacturing (AM) revolutionized many industries, i.e., Automotive, Biomedical, Aerospace and Defense. As opposed to traditional manufacturing methods, a part is manufactured layer by layer from 3D CAD models in AM. Though the vision of AM is impressive, there are many challenges that are hindering the widespread use of these complex parts. One of the main challenges is its strength that varies with different manufacturing parameters. We are going to investigate the effect of build parameters on the mechanical, electrical and crystalline properties of the additively manufactured heterogeneous material system. The goal of the thesis is to find a correlation …
Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai
Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai
Mechanical and Aerospace Engineering Theses
Improvement to an existing design is an ongoing and never-ending process in every field. The improvement can be in a myriad of areas like an increase in strength, reduction in weight, stiffness to a loading condition and so on. The way it is achieved can range from changing the properties of the material used by incorporating various manufacturing processes or by using an alternative material which can sustain the same loading conditions or for that matter, work better than the existing material. Composite materials like Carbon Fiber, Glass Fiber or Kevlar Fiber reinforced plastics, to name few, are being used …
Investigation On Effective Modulus And Stress Concentration Factor Of 3d Reinforced Composite By Finite Element Analysis Method, Chandra Bhaskar Reddy Pittu
Investigation On Effective Modulus And Stress Concentration Factor Of 3d Reinforced Composite By Finite Element Analysis Method, Chandra Bhaskar Reddy Pittu
Mechanical and Aerospace Engineering Theses
Micromechanics of Composites aims to analyze the localized stresses inside any given constituents of the composite structure. This Thesis is focused on Calculating the effective modulus and the Stress concentration factor of the 3D straight Fiber Composite using Finite Element(FE). The compressive and a Shear response of a 3D Straight fiber composite comprising three directional E Glass Fibers reinforced in an epoxy matrix is analysed. This result is the 10% of overall Composite Ductility and a 10% of overall Shear displacement load in the orthogonal directions. FE calculations are reported to analyse the response of 3d reinforcement as of with …
Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal
Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal
Mechanical and Aerospace Engineering Theses
Hinges are the most commonly used mechanical bearings to connect 2 objects for relative rotational motion. Modern day aerospace hinges are generally made using either Aluminum, Steel or bronze. The study analyzes the use of composite material as an alternative to traditional materials for manufacturing these hinges. The research is focused on the Finite element Analysis of a composite hinge as well as an aluminum hinge. The load capacity of both the types of hinges are compared. To improve the design of the composite hinge, a combination of composite material and aluminum is used to model a hybrid hinge design. …
Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma
Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma
Mechanical and Aerospace Engineering Theses
Car’s safety is most important structural criteria while designing an automotive chassis. To protect the occupants from a direct impact, the passenger cabin and the structure of the vehicle should have an appropriate stiffness so that the it absorbs any kind of impact and keeps the passenger safe. Design standards are set by various vehicle safety association around the world based on different crash situations i.e. front crash, side impact, roll over etc. Among these standards, side impact crash account for over all 40% crashes all around the world and is one of the most fatal crash scenarios. This research …
Finite Element Analysis Of Composite Reactor Pressure Vessel, Tejas Vasant Mhetre
Finite Element Analysis Of Composite Reactor Pressure Vessel, Tejas Vasant Mhetre
Mechanical and Aerospace Engineering Theses
Reactor Pressure Vessel is the container designed to hold gases or liquids above atmospheric pressure. The focus of this study is to develop Finite Element Model to predict the performance of composite reactor pressure vessel subjected to extreme pressure and temperature and compare with pressure vessel manufactured using conventional materials. In the first part of the study, a pressure vessel system with Carbon steel material under design pressure and temperature have been analyzed for stresses, deformation and Safety Factor. Various loading cases have been discussed during the analysis of pressure vessel. Composite materials have been a suitable replacement to the …
A Micromechnics Approach To Predicting The Onset Yielding Envelope Of Particulate Composite Materials, Behrooz Karimi
A Micromechnics Approach To Predicting The Onset Yielding Envelope Of Particulate Composite Materials, Behrooz Karimi
Mechanical and Aerospace Engineering Dissertations
Composite materials fail for various reasons and extensive research has been conducted both experimentally and theoretically. However, theoretical prediction of composite failure by yielding seems scarce. Adding reinforcing elements to matrix significantly affects the structural behavior of composite materials. The inserted particles on one hand obstruct the progress of cracks and on the other hand cause stress concentration on the interface of the particle-matrix and eventually influence the ultimate strength of the material. In this research, we study the interface stresses and strength in particulate reinforced composites under uniform mechanical and thermal loading. We theoretically obtain failure envelopes for particulate …
Strength And Damage Prognosis Of Adhesive Bond And Inter-Ply Hybrid Composites Based On Dielectric Properties, Priyanshu K. Banerjee
Strength And Damage Prognosis Of Adhesive Bond And Inter-Ply Hybrid Composites Based On Dielectric Properties, Priyanshu K. Banerjee
Mechanical and Aerospace Engineering Theses
Composite materials have found their applications in a wide range of industries particularly in the aerospace and automotive sectors. This is because they are comparatively light-weight and provide a much better corrosion and wear resistance as compared to other ceramics and metals. Adhesive bonding can be used to improve the stress distribution between these composite materials. Moreover, adhesive bond decreases the weight and concentration of stresses in the structure. Broadband Dielectric Spectroscopy, BbDS is a robust tool used for analyzing the dielectric properties of a polymer composite. This method can be used to monitor the curing process of the specimen. …
Investigation On Metal-Composite Hybrid Flywheels Using Finite Element Method, Ching Huai Wang
Investigation On Metal-Composite Hybrid Flywheels Using Finite Element Method, Ching Huai Wang
Mechanical and Aerospace Engineering Theses
This research is aimed to investigate the kinetic energy storage of a hybrid metal-composite flywheel rotating at high speeds. The upper limit of energy, which flywheel can supply, is restricted by the strength of material because both energy and stress are proportional to the density of the material and the square of the velocity. Metal flywheels operate at lower rotational speed and supply less energy than the composite flywheels. Composite flywheels have a very high density per unit mass, but lower energy density per unit of the design volume. The ultra-high speed of composite flywheels creates some engineering challenges such …
Advanced Methods Of Nondestructive Inspection Of Composite Structures Based On Limited Angle X-Ray Computed Tomography, Ekaterina Bostaph
Advanced Methods Of Nondestructive Inspection Of Composite Structures Based On Limited Angle X-Ray Computed Tomography, Ekaterina Bostaph
Mechanical and Aerospace Engineering Dissertations
This research aimed to study the potential for breaking through object size limitations of current X-ray computed tomography (CT) systems by implementing a limited angle scanning technique. CT stands out among other industrial nondestructive inspection (NDI) methods due to its unique ability to perform 3D volumetric inspection, unmatched micro-focus resolution, and objectivity that allows for automated result interpretation. This work attempts to advance NDI technique to enable microstructural material characterization and structural diagnostics of composite structures, where object sizes often prohibit the application of full 360o CT. Even in situations where the objects can be accommodated within existing micro-CT configuration, …
Analysis Of Composite Structures With Curvature Under Temperature Environment, Muthu Ram Prabhu Elenchezhian
Analysis Of Composite Structures With Curvature Under Temperature Environment, Muthu Ram Prabhu Elenchezhian
Mechanical and Aerospace Engineering Theses
Composite structures are frequently exposed to environments with change in temperatures during their service life. The thermal behaviours of the laminated composite structures are more pronounced than that of the structures made of isotropic materials. For the structures under thermal environment, extensive studies have been conducted to investigate the induced thermal stresses and deformation of composite laminated plates by linear/non-linear analysis and composite structures by finite element analysis. The main focus of this study is concentrated on development of an analytical method for analyzing composite thin shells and/or moderate curved beam structures under temperature environment. This includes the derivation of …
Load Carrying Capacity Management Of Compound Anisotropic Composite Rings Under External Pressure, Salman Bakhrayba
Load Carrying Capacity Management Of Compound Anisotropic Composite Rings Under External Pressure, Salman Bakhrayba
Mechanical and Aerospace Engineering Theses
Composites have much higher strength than conventional materials such as steel. This makes it attractive to replace heavy loaded structural elements, made traditionally from steel, by elements made from composites. However, it is not a trivial task for statically indeterminate structures due to anisotropy of elastic and strength properties of composites. Present investigation is done for a ring subjected to external load. Such rings are used as bulkheads in many applications. Dependence of ultimate external pressure on thickness of the ring is nonlinear one. It is related to non-uniformity of distribution of circumferential stresses, with anisotropy of material, with set …
Finite Element Analysis Of Composite Aircraft Fuselage Frame, Aditya Milind Dandekar
Finite Element Analysis Of Composite Aircraft Fuselage Frame, Aditya Milind Dandekar
Mechanical and Aerospace Engineering Theses
Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. …
Thermal Stress Analysis Of Unidirectional Composite Material By Fem Modeling, Gopal D. Gulwani
Thermal Stress Analysis Of Unidirectional Composite Material By Fem Modeling, Gopal D. Gulwani
Mechanical and Aerospace Engineering Theses
Micromechanics of composite is study of complex mechanism of stress and strain transfer between fiber and matrix within a composite as well as distributions of physical fields inside heterogeneous medium. It was used successfully in predicting accurately physical properties like effective stiffness, effective linear thermal expansion of heterogeneous materials like composite. However, when it comes to strength characteristics of composite especially in transversal direction it failed to predict more accurate results. This thesis is focused on thermally induced stress analysis of unidirectional composite by finite element method. Thermal stresses which are dangerously ignored factor in mechanics of composite usually occur …
Static And Dynamic Fea Analysis Of A Composite Leaf Spring, Himanshu Arun Raut
Static And Dynamic Fea Analysis Of A Composite Leaf Spring, Himanshu Arun Raut
Mechanical and Aerospace Engineering Theses
Composite materials are widely used in aeronautical, marine and automotive industries, because of their excellent mechanical properties, low density and ease of manufacture. Due to this increasing trend to utilize composite materials, it has become necessary to investigate the pros and cons of composites. This research investigated the static and dynamic behaviors for a composite leaf spring that are used in Chevrolet Corvette Grand and light tractor-trailers. The objective of this study was to find the cause of de-lamination/ failure of the unidirectional composite layers in varying cross sections of the leaf spring. Finite element method is used to calculate …
Effect Of Structural Variations On Thermal Deformation Of Single Curvature Composite Sandwich Panels, Brady C. Lotz
Effect Of Structural Variations On Thermal Deformation Of Single Curvature Composite Sandwich Panels, Brady C. Lotz
Mechanical and Aerospace Engineering Theses
Composite structures cured at a high temperature in a contoured female mold have a tendency to deform or spring-in when brought down to room temperature from cure temperature. This thesis investigates the effects of various structural parameters on the spring-in of the curved shape of a composite sandwich panel due to thermal deformation. A finite element model of a single curved composite sandwich panel is developed using 3D shell elements and validated against other published articles and classical lamination theory. Using a control structure of AS4/3501-6 carbon/epoxy with half inch Nomex honeycomb core with a layup of [0°/90°/0°/90°/Core/90°/0°/90°/0°]T, structural parameters …